As Neatorama says of this lan­guage map of Europe:

Lan­guages cor­re­spond only impre­cisely with polit­i­cal bor­ders, which are des­ig­nated by the super­im­posed red lines.

The Eng­lish ver­sion of this map was cre­ated by Post­mann Michael in 2007 […] and there are con­tin­u­ing doubts regard­ing the accu­racy of some of the lan­guage borders.

I am reminded of this equally won­der­ful graphic depict­ing the evo­lu­tion of the Indo-European fam­ily of lan­guages.